The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art.
Loss-in-weight feeders, gain-in-weight feeders, and weigh belt feeders can be used to measure the flow of bulk solid materials. Loss-in-weight feeder systems can include a hopper and a feed mechanism that can be continuously weighed, for example, using load cells. As the feed mechanism discharges material from the hopper, mass of the system decreases. A controller can adjust speed of the feed mechanism to maintain a rate of weight loss that matches a desired feed rate. Gain-in-weight feeder systems are similar, and can include a hopper and a feed mechanism that can be continuously weighed. As the feed mechanism discharges material into the hopper, mass of the system increases, and speed of the feed mechanism can be adjusted to maintain a rate of weight gain that matches a desired feed rate. Weigh belt feeder systems can operate by continuously weighing a moving bed of bulk material, and controlling belt speed to maintain a desired feed rate.
Further, vibratory conveyors and belt conveyors are conveyor mechanisms that can be used to convey bulk solid materials. A vibratory conveyor can include a carrying deck or tray and a drive mechanism. The drive system imparts to the deck a vibrating action, and the bulk material on the deck is moved along the deck by means of the vibrating action. A belt conveyor can include two or more pulleys, and a conveyor belt rotating between the two or more pulleys. One or more of the pulleys are driven to move the conveyor belt forward.